Wednesday, July 4, 2018

ERROR: Failed to create collection 'myhdfscore1' due to: create the collection time out:180s

When trying to create a collection in solr getting the below error

"ERROR: Failed to create collection 'myhdfscore1' due to: create the collection time out:180s"

To resolve this

Login to ambari console and stop Ambari infra

Stop Zookeeper

Start Zookeeper 

Start Ambari Infra

Now try to create the collection again

Integrating solr with banana in hortonworks

Download and extract banana

Copy banana folder to $SOLR_HOME/server/solr-webapp/webapp/

Creating a collection for banana:

banana url:

Postgresql on linux

By default, we will get postgresql on Linux installation

Check for the status of postgresql service as below

Before starting the postgresql service initialize the database as below

Enable the firewall for postgresql as below

Start the service and check for the status as below

Now postgresql is up and running.

Granting permissions for root user to run postgresql

Steps for creating postgresql user:

Change to postgres user and run the below command
$createuser --pwprompt

Give username and password and enter "y" and click enter

Creating postgresql database:

Now we can create postgresql database as a root user as below

Connect to the newly created database as below:

Tuesday, July 3, 2018

Finding files that use the most disk space in linux

Command to list the top 10 largest directories from the current path

du -sh * | sort -hr | head -n10

Database crashed, unable to connect through sqlplus ; ORA-01012: not logged on ; Oracle Instance alive for sid "orcl"

When trying to start the database getting the below error:

ORA-01012: not logged on
Process ID: 0

Session ID: 0 Serial number: 0

To resolve this exit from the database first

Run SYSRESV Utility as below:

Remove damaged Semaphores and shared memory as below:

Try to connect the database now

Command to unzip all the zip files in a directory in Linux

Below is a directory containing 5 zip files

To extract all the zip files at a time run the below command
#unzip \*.zip

Tuesday, June 26, 2018

Step by step uninstalling Ambari server

Checking which user is running the Ambari server

ps aux | grep ambari-server

Checking the version of Ambari server installed

rpm -qa | grep ambari

Stopping the Ambari server

Reset the Ambari server

Dropping the schema

Removing the Ambari server

Deleting the Ambari server files and directories

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